GNURLOPT_PROXY_CAINFO(3)

💅 GNURLOPT_PROXY_CAINFO(3) 💅

okay so bestie, this page is from the curl_easy_setopt options manual, and it's all about GNURLOPT_PROXY_CAINFO(3) — aka the path to your proxy Certificate Authority (CA) bundle. no cap, this one is niche but important 💖

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🎀 NAME 🎀

CURLOPT_PROXY_CAINFO — path to proxy Certificate Authority (CA) bundle. that's the whole name, and it ate ✨

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✨ SYNOPSIS ✨

#include <gnurl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_CAINFO, char
*path);

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🦋 DESCRIPTION 🦋

okay so first thing: this option is for connecting to an HTTPS proxy, not an HTTPS server. like, read that again, bestie — proxy vibes only 💅

You pass a char * to a null-terminated string naming a file holding one or more certificates to verify the HTTPS proxy with.

If CURLOPT_PROXY_SSL_VERIFYPEER(3) is zero and you avoid verifying the server's certificate, CURLOPT_PROXY_CAINFO(3) need not even indicate an accessible file. lowkey wild but that's the rule 🫶

This option is by default set to the system path where libcurl's cacert bundle is assumed to be stored, as established at build time. built-in behavior, bestie ✨

If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module (libnsspem.so) needs to be available for this option to work properly. so yeah, that module has to show up to the function. periodt.

(iOS and macOS only) If curl is built against Secure Transport, then this option is supported for backward compatibility with other SSL engines, but it should not be set. If the option is not set, then curl will use the certificates in the system and user Keychain to verify the peer, which is the preferred method of verifying the peer's certificate chain. so like… don't set it there, okay? the Keychain method is the main character 🌈

The application does not have to keep the string around after setting this option. you can let that string go, bestie, it's fine 💀

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🌸 DEFAULT 🌸

Built-in system specific — that's literally the default, system-specific and built in, slay ✨

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💜 PROTOCOLS 💜

Used with HTTPS proxy. that's it. that's the protocol mood 🎀

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🔥 EXAMPLE 🔥

okay so here's the example, and yes we're keeping it exactly as it is:

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
  /* using an HTTPS proxy */
  curl_easy_setopt(curl, CURLOPT_PROXY, "https://localhost:443");
  curl_easy_setopt(curl, CURLOPT_PROXY_CAINFO, "/etc/certs/cabundle.pem");
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}

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⭐ AVAILABILITY ⭐

Added in 7.52.0.

For TLS backends that don't support certificate files, the CURLOPT_PROXY_CAINFO(3) option is ignored. Refer to https://curl.haxx.se/docs/ssl-compared.html. so if your backend doesn't do certificate files, this option is just gonna sit there like 🙈

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🍓 RETURN VALUE 🍓

Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space. those are the three outcomes, no cap 💅

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👑 SEE ALSO 👑

• CURLOPT_PROXY_CAPATH(3)
• CURLOPT_PROXY_SSL_VERIFYPEER(3)
• CURLOPT_PROXY_SSL_VERIFYHOST(3)
• CURLOPT_CAPATH(3)
• CURLOPT_SSL_VERIFYPEER(3)
• CURLOPT_SSL_VERIFYHOST(3)

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xoxo, bestie — this page is from libcurl 7.52.0, dated 16 Nov 2016, and it's literally the GNURLOPT_PROXY_CAINFO(3) page. 💖✨🎀